School of Earth, Environmental, & Marine Sciences Faculty Publications

Document Type

Article

Publication Date

12-1-2026

Abstract

Rapid and unplanned urbanization has significantly transformed land use/land cover (LULC), contributing to increased land surface temperature (LST) and the emergence of urban heat islands (UHIs), especially in ecologically fragile regions. This study focuses on the Sylhet Division of Bangladesh, assessing LULC changes, LST dynamics, and UHI expansion from 1994 to 2024 using Landsat satellite imagery, normalized difference vegetation index (NDVI), normalized difference water index (NDWI) indices, and field-based LST validation. Unsupervised classification reveals a 191.75% increase in settlement areas and a 25.65% loss in forest cover. Correspondingly, the highest LST zones (> 30 °C) were absent in 1994 but expanded to over 19,000 ha by 2024, while the coolest class (< 20 °C) nearly disappeared. Ground-truthing at 100 points yielded a high validation accuracy (overall 89%, Kappa = 0.86), and the correlation between field and satellite-derived LST values showed a strong coefficient of determination (R² = 0.80). Pearson correlation analysis indicated that built-up and agricultural areas are strongly positively correlated with higher LST classes (r = + 0.92 to + 0.98), whereas forested regions and water bodies exhibit strong negative correlations (r = − 0.89 to − 1.00). These results highlight a clear association between anthropogenic land transformation and thermal intensification. This study not only offers a spatiotemporal understanding of thermal landscape shifts in Sylhet Division but also provides a robust remote sensing-ground validation framework for urban heat risk assessment. The findings can inform climate-sensitive planning, green space restoration, and sustainable land-use strategies in rapidly urbanizing tropical regions.

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Publication Title

Discover Geoscience

DOI

10.1007/s44288-026-00687-z

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